In Brawl, he mostly plays King Dedede, and was perpetually considered to be one of the best King Dedede mains in the world throughout its entire competitive life, at times being considered the absolute best in debate with Coney. But he was also known for playing a large variety of other characters at a high competitive level, including Meta Knight, Wario, Falco, Ice Climbers, Fox, and Wolf. He notably placed 5th in Brawl singles, 3rd in doubles, and 2nd in regional crews at Apex 2009. He has taken sets off of top professional players such as Ally, ADHD, UltimateRazer, MJG, Mr.R, Vinnie, Trela, Fatal, and ANTi.

Unlike many other renowned Brawl players, Atomsk did not fully move on to Smash 4 after the demise of Brawl's competitive scene, with his Smash 4 tournament activity being scarce and his ability in it being at a significantly lower level. Instead Atomsk focuses on Melee nowadays, including travelling to GENESIS 4 to enter only Melee.